The measles outbreak that began at the Disney theme parks in Anaheim in December and sickened 131 Californians and others across the country has been contained here, state health officials announced this morning.
The California Department of Public Health made the determination after two 21-day incubation periods passed without any new measles cases reported.
"We are pleased this outbreak is over, but caution that measles can be reintroduced in California at any time when an infected person brings it to the state," Department of Public Health Director Dr. Karen Smith said in a statement. "The best defense for protection against the highly infectious measles is vaccination."
Measles was declared eliminated from the United States in 2000. But health officials believe a tourist brought the measles to the theme parks between December 17 and 20, 2014, infecting 42 Disneyland and Disney California Adventure visitors.
As the disease spread from those who contracted it at the parks to others across the state and country, the outbreak shined a light on low vaccination rates in some communities.
It also spurred a bill in the state legislature - SB 277 - that would eliminate parents’ right to opt out of vaccinating their children due to philosophical or religious beliefs. The measure has sparked heated debate between supporters, who see it as a public health imperative, and opponents, who say it would deprive parents of the choice of vaccinating their children.
Southern California was the epicenter of the outbreak, with 35 cases reported in Orange County, 28 in Los Angeles County, 14 in San Diego County, 13 in Ventura County and 12 in San Bernardino County.
Beyond the 42 people who contracted measles while visiting the theme parks, 30 more who contracted it were their close contacts. Eleven people were exposed in settings - like emergency rooms - where a sick person was present. Health officials are unsure when another 44 were exposed to the disease.
No deaths resulted from the outbreak.
Among the cases with known vaccination status, 56 people were unvaccinated, and 25 had one or more doses of the MMR vaccine, which protects against measles, mumps and rubella.
The public health investigation into the measles outbreak was significant, according to the state health department. Local and state laboratories conducted tests on more than 1,000 people.
"Prompt investigation of cases, interviewing hundreds of contacts of infected people, vaccinating hundreds of at risk people, and increasing awareness among health care providers about measles, helped to control this outbreak," Dr. Smith said.
The highly contagious disease can live for up to two hours on a surface or in the air in an area where an infected person coughed or sneezed. If one person has the disease, 90 percent of the people close to that person who are not immune will also become infected, according to health experts.
Infected people are usually contagious from four days before they develop a telltale rash to four days afterward.
While this outbreak is over, it does not mean that there will not be future measles cases reported in California, the health department said.